1. Field of the Invention
The invention relates to articulated couplings and more particularly the sliding elements of such couplings.
2. Description of the Relevant Art
Articulated couplings are used when, occasionally, it is necessary to allow an angular range of movement between two ducts.
International patent application WO02/084164 teaches of a swivel coupling including a female endpiece having a substantially spherical end, a male endpiece, an elastic pressure member, and inner and outer rings making it possible to keep the various parts in position.
The inner ring is situated particularly between the substantially spherical end and the shoulder. Said ring ensures that the spherical portion of the female endpiece slides relative to the other parts. The inner ring is made in one piece and has great sensitivity to the external stresses. Such stresses cause cracks and flaking of said inner ring and/or of said outer ring.
It is desirable to remedy the problems of flaking of the element providing the sliding action.